1. Field of the Invention
This invention pertains to a floating boom for collecting floatable material, such as liquid hydrocarbons, floating on the surface of a body of water, and more particularly to an inflatable boom which, through its configuration, requires a small amount of inflation air volume to achieve the buoyancy necessary to float the boom.
2. General Background
Conventional oil booms normally comprise an elongated tubular body, generally produced by inflation of a fluid impervious tube to which is secured a depending oil confining skirt. These booms are normally stored on land or on ship in a collapsed state either by flat folding the collapsed tube or by rolling the collapsed tube on to a reel. See, for example, U.S. Pat. Nos. 2,682,151 and 3,494,132 which disclose a series of inflatable plastic tubes, the ends of which are interconnected by sleeves. Integrally formed on each tube is a depending hollow skirt or fin having a weighted material (for ballast) such as lead shot or chain contained in or attached to the lower longitudinal edge of the fin.
Other patents, such as U.S. Pat. No. 4,123,911, disclose a continuous inflatable tube that must be inflated to achieve the required degree of buoyancy necessary to float the boom. These types of inflatable booms, while functional, require a large volume of pressurized air for inflation and operation. Supplying such pressurized air in a marine environment is both a costly and time consuming procedure. Furthermore, for those designs incorporating one single tube or a series of long single tubes, should a leak occur in the tube, the result would be a total loss of buoyancy in that length of tubing.
An alternate method of achieving the desired degree of water displacement so as to float the boom is disclosed in U.S. Pat. Nos. 4,068,478 and 4,295,755. Both of these patents disclose the use of a pre-shaped spiral wire form that is inserted within the tube during manufacturing. This wire form compresses and is able to slide within the tube so that the boom can be rolled on a reel, yet, when the tube is unrolled, the wire form expands thereby stretching the tube to its desired shape. In order for the tube to expand, there must be vent openings in the tube for the unrestrained movement of air into and out of the tube. Thus, the buoyancy of this boom do not rely upon inflation or pressurization of the tube. Additionally, when the wire form is compressed or wound on the reel for long periods of time, its ability to expand outwardly is decreased, thereby rendering the boom less effective. Furthermore, such wire forms considerably increase the bulk and weight of the boom, thereby requiring more storage space and more water displacement to float the boom. Another drawback is the ability of water to enter the boom through these vent openings, thereby flooding the tube and consequently sinking the boom. Additionally, the consequences of the wire form breaking either during storage or during use should be considered. It might be that a sharp edge will pierce the tube, thereby undermining the buoyancy of the boom.
It is thus an object of this invention to provide a boom that is not bulky when stored, will not lose its expansion capabilities when stored for long periods of time, and does not incorporate wire forms that might break, thereby possibly piercing the tube.
Another object of this invention is to devise a boom that does not require a large volume of inflation air to achieve the desired degree of water displacement.
A further object of this invention includes the ability for one section of the boom to become ruptured without rendering the boom useless or unmanageable.
Another object of this invention is the ability that should water enter this tube through vent openings, the accumulation of such water will not render the boom or this section of the tube ineffective. These and other objects of this invention will become obvious upon further investigation.